(1) Technical Field
The present invention relates to computer storage systems, such as data storage devices that use data recovery.
(2) Description of Related Art
Typically, a storage system experiencing power failure at the middle of a process either acquires corrupted data or loses the data in a worst case scenario. The usual technique of easy data recovery is that upon data modification, the controls and directories associated to the data are also updated. This type of technique consumes relatively larger time and bandwidth. Consequently, there is a need for efficient power cycle sequences capable of data recovery.
The directory structure of a hybrid storage system is very hierarchical. This structure includes controls and directories arranged in a linked list manner. Constant updates of these directories are not only very time and bandwidth consuming but moreover, update synchronization is difficult considering the different directory levels that are contained in different memory blocks. Consequently, there is a need for sequences that are sufficiently adaptive to determine when these directories need to be updated and when the directories require no updates, thereby minimizing directory updates.
Normally, the control information is contained in the control blocks alone. Putting the controls in one block allows rebuilding of all directory structures, and this rebuilding even includes the rebuilding of unrelated information. This results in the wasting of time and bandwidth during the rebuilding process. Consequently, there is a need to achieve an improved and more efficient rebuilding of control data that has been corrupted.